When a TFT-LCD (Thin Film Transistor-Liquid Crystal Display) panel displays a low grey level image, there usually appears a poor display quality, so called as a two-side whitening, wherein the brightness in two-side area of the TFT-LCD is high and the brightness in the middle area of the TFT-LCD is low.
The reason why the two-side whitening occurred is that, as shown in FIG. 1, the driving voltage of the Gate line 11 is input from the scan driving electrode (Gate COF) 12 on the left and right side of the liquid crystal display panel 10, and the resistor R and capacitor C of the Gate line 11 results in RC delay, such that the voltage normally input from the two sides is distorted when it is transmitted to the middle area A, i.e. the Gate wave is distorted. The distorted voltage would reduce the charging ratio in the middle area A so that the brightness at the middle area A is lowered. At this time, the brightness at the two-side areas B1 and B2 is higher than the brightness at the middle area A, i.e. the two-side whitening occurs. The two-side whitening is more obviously when displaying a low grey level image due to sensitivity of human eyes.